Projections released by the Air Transport Association of America suggest that only about 23.2 million people will travel by plane during the 12-day period surrounding Thanksgiving, a drop of two percent from last year. But this doesn’t mean travelers should expect to see empty seats on their flights to grandma’s house.

The trade group says that airlines are reducing capacity and limiting the number of seats available for sale, in order to match the lower demand. John Heimlich, vice president and chief economist for the association said, “For the busiest holidays, it’s always good counsel to book early and book often. Based on published airline schedules, these cuts are expected to continue through the winter.”

Even though airlines are reporting higher revenues, the association warned that 2011 could be worse financially than last year for the airlines because higher costs are outpacing higher revenues. According to the group’s report, fuel costs alone rose 38 percent for the first nine months of the year and were the largest driver of expenses.

Heimlich said that slim margins mean carriers actually keep less than a penny in profit for every dollar of revenue and that “given these facts and the commercial situation, it’s not surprising that as the year has gone by we’ve seen a trend toward reduction of seating capacity.”

The busiest travel days during Thanksgiving are expected to be Friday, November 18; Sunday, November 27; and Monday, November 28. The least traveled day will likely be Thanksgiving day itself, according to the association.